Overview
What Is a Marathon Time Predictor?
This tool estimates your marathon finish time based on a recent race performance at a shorter distance, using a standard race-time prediction formula.
Predict your marathon finish time from a recent race.
This tool estimates your marathon finish time based on a recent race performance at a shorter distance, using a standard race-time prediction formula.
Useful for setting a realistic marathon goal time based on current fitness demonstrated at shorter distances.
Input the distance of a race you recently completed.
Input your time for that race.
The estimate updates automatically.
It provides a reasonable estimate based on a standard formula, though actual marathon performance depends on endurance-specific training beyond raw speed.
Riegel's formula, a widely-used race time prediction model based on a power-law relationship between distance and time.
No, this is a mathematical prediction from shorter race pace - actual results depend heavily on your specific marathon training (long runs, fueling, etc.).
A recent race at a meaningful distance (10K, half marathon) run at genuine effort gives a more reliable prediction than a very short sprint distance.
No, calculations happen entirely in your browser.
Marathon-specific endurance, pacing strategy, weather, course difficulty, and fueling all significantly affect actual results beyond this basic prediction.
Use it as a general reference - many runners find their actual marathon pace differs somewhat from pure mathematical predictions.
Predictions are often most reliable for runners with substantial endurance base training; the formula may be less accurate for those without much distance running experience.
Yes, this is a common practical use for establishing a realistic starting goal pace for marathon training.
Yes, completely free with no sign-up required.